Flask for dental molds



15, 1933- o. T. BIRDLEBOUGH 1,922,875

FLASK FOR DENTAL MOLDS Filed Sep a. 26, 1951 INVENTOR Patented Aug. 15, 1933 FLASK FOR DENTAL MoLDs Otis T. Birdlebough, Yakima, Wash.

Application September 26, 1931 Serial No. 565,260

3 Claims. (CI. 18-33) My invention relates to mold flasks and more particularly to those of the type employed in connection with dental molds.

With the type of dental mold flask heretofore employed, difficulty has been experienced in effecting convenient removal of the plaster without damage to the flask, particularly because the flasks are usually made of bronze or other.

material that frequently becomes dented or bent during the hammering and prying loose of the plaster, with the result that flask members do not fit perfectly thereafter and subsequent dentures cannot be formed to accurate shape.

One object of my invention is to provide a mold flask of such form that the plaster or other mold material can be removed therefrom in an expeditious manner with a minimum of danger and with little likelihood of injury to the mold Another object of my invention is to provide a mold flask of such form and strength that there minimum danger of deformation thereof through warping Ol' OlJh6lWlSe, and wherein the parts of the flask can be used repeatedly with assurance that no misfits will occur.

One form which my invention may take is shown in the accompanying drawing, wherein Figure 1 is a plan view of the flask with the cover removed; Fig. 2 is a front elevational view of the completely assembled flask; Fig. 3 is a side elevational view thereof; Fig. 4 is a View taken on the line IVIV of Fig. 2; Fig. 5 is a view taken on the line V-V of Fig. 2, and Fig. 6 is an inverted plan view of the cover plate.

The flask, in size and general appearance, corresponds to those previously employed, but various improvements as hereinafter described have been designed by me and incorporated in the flask as hereinafter described and claimed.

The flask consists primarily of what may be termed a lower half '7, an upper half 8, and a cover plate 9. r

The cavity in the upper half of the flask is of somewhat tapering form, and the walls are curved or rounded both interiorly and exteriorly, and the rear wall is thickened at its mid portion as shown more clearly in Fig. 1, the cavity flar ing toward the lower edge of the upper half edge of the flask member 8, and has depending flanges 9a abutting the rear wall of the flask, to hold the cover centered in position. These lugs 10 will become partially embedded in the plaster and the cover thereby held against accidental displacement. The cover is provided on its underside with a series of grooves 12 that permit surplus plaster to be forced out of the mold during the pressing of the die into the plaster. The member 8 has a pair of integrallyformed pin-like portions or members 13 that fit into the curved recesses 14 of the bottom flask when the two flask members are brought together in assembled position.

The lower flask member '7 is provided with a removable bottom plate 15 of sheet metal or other suitable material, one end of which overlies the innerend of a gate member 16 which is of strip-like form and whose outer end lies in a recess formed in the upper edge of the flask member 7 as shown more clearly in Fig. 2. The gate member is slidably supported in the lower flask cavity, and covers an opening or gate 1'7 that is provided in the wall of the flask member 7 to permit a screw driver 18 or a similar implement to be inserted beneath the member 16, so that the plaster which is supported by the false bottom plate 15 can be conveniently pried loose from the side Walls of the lower mold cavity, the said cavity, of course, flaring somewhat toward the horizontal dividing line of the mold as in the case of the upper mold cavity.

Not only does the curved and flared contour of the respective flask members permit of easy removal of the plaster, but the flask when assembled will withstand greater pressures than in the case of the ordinary flask whose sides are approximately straight along vertical lines.

I claim as my invention:--

l. A mold flask member having side walls and a bottom wall, a removable plate supported by the bottom wall, the one side wall being provided with an opening adjacentto the bottom wall, and a separately formed gate member positioned across said opening and havmg a Zontal portion extending beneath the said plate,

side wall, adjacent to the bottom of said member, and a movable gate extending across said opening, the said gate being provided with a horizontally-extending portion positioned to rest on the bottom of the flask member and with a horizontally-extending lip extending into said recess.

OTIS T. BIRDLEBOUGH. 

